1. Field of the Invention
Apparatuses and methods consistent with the present invention relate to a motion estimator and a motion estimating method, and more particularly, to a motion estimator and a motion estimating method for estimating frame motion in order to generate an interpolation frame to be inserted between two adjacent frames.
2. Description of the Related Art
In general, a frame rate conversion refers to converting a frequency of an input video signal to a frequency matching an output format. To this end, for example, additional frames are inserted between original frames to convert a video signal of 50 Hz to a video signal of 100 Hz. If the original frames are merely repeated or a temporal linear interpolation method is used for the frame rate conversion, a motion blur effect or the like may occur. Therefore, it is common that a motion estimation and compensation technique is used as one of high quality frame rate convertion methods effective in reducing such a motion blur effect.
In recent years, various frame interpolating methods using such a motion estimation and compensation technique have been actively developed.
Related art motion estimation methods define a plurality of candidate motion vectors, select a final motion vector on the basis of a motion prediction error value, and generate an interpolation frame based on the selected final motion vector. The related art motion estimation methods estimate motion on the assumption that a candidate motion vector represents expected motion for a reference block provided in a current frame and the final motion vector corresponding to real motion of the frame has a minimal motion prediction error value.
However, in the related art motion estimation methods, a vector, which does not represent real motion, may be wrongly estimated as the final motion vector, and if the candidate motion vectors predict motion of the reference block wrongly, motion vectors may continue to be wrongly estimated. In addition, the above-mentioned motion blur effect may be further increased.